Washing machine

ABSTRACT

The invention relates to a washing machine and particularly to the mounting of a motorized multispeed gear unit on the end wall of the tub of the washing machine. The tub end wall is conically shaped to provide sturdiness and a mounting bracket is provided for attaching the gear unit to the tub end wall. The gear unit has an eccentrically disposed shaft and the mounting bracket has a saddle for holding the gear unit in selected positions so that the distance of the axis of the gear unit from the main shaft of the washer may be varied in order to properly tension a drive unit to a pulley on the main shaft of the washer.

States Ptent 115] 3,645,117 Larsen 1 Feb. 29, 1972 [54] WASHING MACHINE 2,296,259 9/1942 Breckenridge ..68/140 X [72] Inventor: Preben Larsen Homphav Denmark 2,399,319 4/1946 Bowen et a1. ..68/24 X [73] Assignee: Danfoss A/S, Nordborg, Denmark Primary Examiner-William 1. Price Attorney-Wayne B. Easton [22] Filed: July 13, 1970 a 211 App]. 110.; 54,165 [571 ABSTRACT The invention relates to a washing machine and particularly to the mounting of a motorized multispeed gear unit on the end [30] Foreign Apphcat'on Pnomy Dam wall of the tub of the washing machine. The tub end wall is July 3, 1969 Germany ..P 19 33 827.3 Y shaped to Pi sturdines and a mounting bracket 15 prov1ded for attaching the gear umt to the tub end wall. The gear unit has an eccentrically disposed shaft and the mounting CC! bracket has a Saddle for holding the g unit in selected p n tions so that the distance of the axis of the gear unit from the Field of Search i Shaft of h washer y be i d in order to p p y [56] R f C ed tension a drive unit to a pulley on the main shaft of the washer.

e erences it UNITED STATES PATENTS 1 Claims, 5 Drawing Figures 2,191,607 2/1940 Cham berlinet a1,. 6L l 4 WASI-IBNG MACHINE The invention relates to a washing machine incorporating a drum, the shaft of which is mounted in a main bearing in the end wall of the tub and carries a drive wheel on a part projecting beyond the bearing, the washing machine also incorporating a motor changeover gear unit which drives this wheel and is fitted to the tub by means of a support.

Washing machines of this kind are known in which the drum is switched over from a slow washing operation to a faster spinning operation with the help of a gear. The output wheel of the changeover gear is connected to the drive wheel of the drum shaft through a belt. The unit is therefore secured to the circumferential wall of the tub in such a way that the drive wheel projects into the zone of the end wall and is disposed in the same plane as the output wheel.

A disadvantage of this arrangement is that the circumferential wall of the tub not only has to be designed to deal with the loads deriving from the washing and drying process, but must be of such stability that it is enabled to support the unit. Furthermore, the known supports are quite complicated, particularly when means for tensioning the belt also have to be provided.

The object of the invention is to provide a washing machine in which stable support of the motor changeover gear unit is achieved in a simple manner.

According to the invention, this object is achieved by securing the support to the end wall of the tub. This end wall is especially designed to be considerably more stable than the circumferential wall of the tub, since it has to carry the main bearing for the washing drum. Consequently, the end wall constitutes an excellent carrier for the motor gear unit. Although the point of attachment of the support to the tub is now nearer to the end of the motor gear unit, as compared with known units, safe suspension of the unit can nevertheless be achieved if a correspondingly stable support is used.

The circumstances are however much more favorable if, as in a further embodiment of the invention, the gear has a speed changeover ratio of at least and preferably more than l3zl, and the axial length of the gear is less than one-half, and preferably less than one-third of the outside diameter of the motor. Small motors can be used if the changeover ratio is large, since the torque is reduced to a greater extent for the washing operation. If, in addition, the axial length of the gear is small, a unit is obtained which is so much concentrated in the zone of the end wall that it can be suspended near its center of gravity or even at its center of gravity.

If the end wall of the tub is of conical form, which is desirable for reasons of providing greater stability, the axial length of the gear should be at most equal to the axial length of the conical end wall, but preferably less than two-thirds of this length.

A short gear of this kind is expediently obtained with the help of a planetary gear disposed in one plane. Here, it is particularly advantageous if the planetary gear has two concentric sets of planetary wheels, and the outer ring is provided with an output belt pulley. A drive of this kind can provide a considerable reduction in one plane and moreover offers the advantage that the outer ring rotates in one direction only if, upon changeover from the direct drive between the sun wheel and the outer ring, the reduction is carried out by maintaining the position of the shaft of at least one planetary wheel. Here, the output belt pulley can be connected by its end face to the outer ring, so that the axial length is only slightly increased, or said pulley can even be formed by cutting a groove in the outer ring.

In a preferred construction, the support bears against a carrier element on one side of which is fitted the motor and on the other side the gear. This results in a very favorable form of division in which the motor and the gear may even be mounted by one end only on either side of the carrier element.

A particular advantage is achieved if the unit incorporates a circular attachment face, off center from the shaft, and the support has an opposite face matching at least one circular section of this attachment face. By turning the entire unit relatively to the support, the output belt pulley is displaced in such manner that the tension of the belt leading to the drive wheel for the drum can be adjusted.

In this arrangement, the support can comprise a vertically extending plate which is reinforced by bent over edges and which engages the unit in the plane of the center of gravity, or in a plane displaced therefrom towards the gear. This plate is a cheap component which can be welded for example to the end wall of the tub.

In one embodiment, the attachment face is cylindrical and the plate has an opposite face in the form of a section of a cylinder, which, at its outwardly curved circumferential ends accommodates a tensioning device surrounding the remaining part of the attachment face.

In another arrangement, the attachment face is formed on a circumferential flange on the unit, and the plate contains a circular cutaway portion with means for clamping the flange.

The invention will now be described in more detail by reference to embodiments illustrated in the drawing, in which:

FIG. 1 shows a fragmentary side view of one embodiment of a washing machine in accordance with the invention,

FIG. 2 is a front view of the portion seen in FIG. 1,

FIG. 3 is a motor gear unit that may be used in accordance with the invention,

FIG. 4 is a schematic illustration of the planetary gear, and

FIG. 5 is a fragmentary side view of another construction of a washing machine in accordance with the invention.

A washtub 1 has a circumferential wall 2 and a conical end wall 3, which carries a bearing for the drive shaft 4 of the drum. On the part of this shaft that projects outwardly beyond the bearing, there is secured a drive wheel 5, which is driven through a V-belt 6 by an output belt pulley 7, which is part of a motor gear unit 8. This unit is secured to the end wall 3 by means of a support 9. The support comprises a plate 10 with tumed-over edges 11, the part 12 of the plate being welded to the end wall 3. At its lower end the plate 10 carries an opposite face 13 which is in the form of a section of a cylinder and is outwardly bent at the ends of its circumference to form flanges 14. Through the flanges there extend the ends of a clamping device 15, which in the present case, consists of two straps l6 and appropriate clamping screws 17. The unit 8 has a cylindrical attachment face 18, which is off center from the shaft of the output belt pulley 7. Consequently, the tension in the belt 6 can be adjusted by turning the unit 8.

As shown in FIG. 1, the support 9 engages the unit 8 near its center of gravity or at a point displaced towards the belt pulley 7.

The motor gear unit 8 is illustrated in more detail in FIG. 3. Its axial length is very small. The attachment face K8 is constituted by a layer of plastics material which surrounds a carrier element 19. A shaft 22 is mounted in the carrier element by means of two ball bearing units 20 and 21. On one side of the carrier element 19, the shaft 22 carries the rotor 23 of the motor 24, and on the other side the sun wheel 25 of a planetary gear 26. The stator 27 of the motor is secured to the carrier element 19 by means of screw bolts 28. A cover plate 29 closes off the motor at the free end face. Arranged in coplanar relationship with the sun wheel 25, are a first set of two-stage planetary wheels 30, a second set of planetary wheels 31 and an outer ring 32. The belt pulley 7 is secured to this outer ring. The planetary gear is protected by a cover 33. The planetary wheels 31 are provided with shafts 34, which are mounted in a flat ring 35. This is equipped with an armature 36, which can be pulled up by an electromagnet 37 fitted in the carrier element l9. Springs 38 fitted on the shafts 34 return the flat ring 35 and the armature 36.

The planetary gear 26 is illustrated again in FIG. 4. With the dimensions illustrated, a reduction of 1:14 is achieved if the centers of the planetary wheels are stationary. When the electromagnet 37 is not energized, the flat ring 35 is coupled to the outer ring 32 by way of a brake lining 39. Consequently, the outer ring 32 rotates at the same speed as the sun wheel 25. When the electromagnet 37 is energized however, the flat ring 35 and the shafts 34 of the planetary wheels 31 are kept stationary through a brake lining 14. In this case, the above-mentioned reduction between the speed of the sun wheel 25 and the speed of the outer ring 32 is obtained.

In the arrangement shown in FIG. 5, the same reference numerals as in the embodiment illustrated in FIGS. 1-4 are used for like components.

The main difference is in the method of fitting the unit 8. This unit has a flange 41, which is attached to the circumference of the carrier element by means of reinforcing ribs 42. The flange has an offcenter attachment face 43. The attachment plate 9 contains a circular cutaway portion 44 and at its lower end has a bent over edge 45, which enables a clamping device 46 to be fitted. Here again, the belt 6 can be tensioned by turning the unit 8.

The planetary gear illustrated uses friction wheels. Toothed wheels could however also be used.

I claim:

l. A washing machine comprising a stationary tub member, said tub member having a generally vertically extending end wall, a bearing in said end wall, a horizontally extending shaft joumaled in said bearing and having a portion thereof projecting outwardly from said bearing, a drive wheel mounted on said shaft portion, a motorized multispeed gear unit, and a support bracket for mounting said gear unit on said end wall, said motorized multispeed gear unit having an annularly shaped carrier frame member, a motor shaft rotatably journaled in said frame member, a motor being mounted on one side of said frame member and said planetary gear set being mounted on the other side thereof, said frame member having a cylindrically shaped external surface eccentrically disposed relative to said shaft, said support bracket having a downward facing saddle with a concave surface having a diameter equal to the diameter of said frame member cylindrically shaped surface, said frame member being mounted in said saddle. 

1. A washing machine comprising a stationary tub member, said tub member having a generally vertically extending end wall, a bearing in said end wall, a horizontally extending shaft journaled in said bearing and having a portion thereof projecting outwardly from said bearing, a drive wheel mounted on said shaft portion, a motorized multispeed gear unit, and a support bracket for mounting said gear unit on said end wall, said motorized multispeed gear unit having an annularly shaped carrier frame member, a motor shaft rotatably journaled in said frame member, a motor being mounted on one side of said frame member and said planetary gear set being mounted on the other side thereof, said frame member having a cylindrically shaped external surface eccentrically disposed relative to said shaft, said support bracket having a downward facing saddle with a concave surface having a diameter equal to the diameter of said frame member cylindrically shaped surface, said frame member being mounted in said saddle. 